1 / 19

Unit 6 Radioactivity and Nuclear Decay

Unit 6 Radioactivity and Nuclear Decay. Nuclear Changes. Chapter 10.1. What is Radioactivity?. Radioactivity. Radioactivity. Radioactive decay is the disintegration of an unstable atomic nucleus into one or more different nuclides .

keith-lawson
Download Presentation

Unit 6 Radioactivity and Nuclear Decay

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unit 6Radioactivity and Nuclear Decay

  2. Nuclear Changes Chapter 10.1

  3. What is Radioactivity?

  4. Radioactivity

  5. Radioactivity • Radioactive decay is the disintegration of an unstable atomic nucleus into one or more different nuclides. • After radioactive decay, the element changes into a different isotope of the same element or into an entirely different element.

  6. Radioactivity • Nuclear radiation is the release of particles from the nucleus during radioactive decay. • These particles can either be alpha, beta, or gammaparticles.

  7. Types of Radiation • Alpha particles can be stopped by paper. • Beta particles can be stopped by aluminum. • Gamma particles can be stopped by lead.

  8. Alpha Decay • Alpha particle (α) is a positively charged particle that consists of two protons and two neutrons and that is emitted from a nucleus during radioactive decay. • This is a helium nucleus.

  9. Alpha Decay (Atomic Mass #) (Atomic #) 3. Since the atomic # = 82, then

  10. Beta Decay • Beta particle (β) is an electron or positronthat is emitted from a nucleus during radioactive decay. • A positron is a positivelycharged electron, NOTa proton.

  11. Beta Decay (Atomic Mass #) (Atomic #) 3. Since the atomic # = 84, then

  12. Gamma Decay • Gamma ray (γ) is a high-energy photon emitted by a nucleus during fission and radioactive decay. • Aphotonis a packet of electromagnetic radiation or energy.

  13. Gamma Decay (Atomic Mass #) (Atomic #) 3. Since the atomic # = 84, then

  14. Neutron Emission • Neutron emission consists of matter that is emitted from an unstable nucleus • Neutronshave no charge, and therefore do not want to interact with other particles.

  15. How old are rocks? • If you were asked to determine the age of a rock, you would probably not be able to do so easily. • How, then, would you go about finding the rock’s age?

  16. Radioactive Decay Rates • One way to find the age involves radioactive decay. • It is possible to predict the time required for half of the nuclei in a given radioactive sample to decay. • Half-life is the time required for half of the sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope.

  17. Half-Life and Exponential Decay • The definition of half-lifetells us that after the first half-life time of a radioactive sample has passed, halfof the sample remains unchanged. • After the next half-life, half of the remaining half decays, so only a quarterof the original element remains. • Of that quarter, half will decay in the next half-life, so only one-eighth will remain unchanged • This relationship is called exponential decay.

  18. Half-life Time Frames

  19. Half-Life Equations Half- Life Fractions 1st = 1/2 # of 2nd = 1/4 HL’s3rd = 1/8 4th = 1/16 5th = 1/32 1st = 1/2 2nd= 1/4 3rd = 1/8 4th = 1/16 5th = 1/32

More Related